Difference between revisions of "EBC Exercise 27 BusyBox"

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m (Static Linking)
(via bitbake: Removed)
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  host$ '''make defconfig'''
  host$ '''make defconfig'''
  host$ '''make -j9'''      # use -j''X'' for ''X-1'' cores
  host$ '''make -j9'''      # use -j''X'' for ''X-1'' cores
=== via bitbake ===
We'll attack getting BusyBox like we did getting the kernel ([[EBC Exercise 01 Using bitbake for Kernel and U-boot]]) though the paths will be slightly different.  Make sure you have commented out
# INHERIT += " rm_work "
in the '''local.conf''' file.  See [[EBC Exercise 01 Using bitbake for Kernel and U-boot]] for details.
Check and see what you already have for previous installations:
host$ '''source  ~/.oe/environment-oecore'''
host$ '''time bitbake busybox'''
host$ '''cd ~/BeagleBoard/oe/build/tmp-angstrom_v2012_05-eglibc/work/beagleboard-angstrom-linux-gnueabi'''
host$ '''ls'''
My bitbake took about 4.5 minutes to download and compile.
When you did ''ls'' did you see '''BusyBox'''?  I didn't.  Do this to find it:
host$ '''cd cd ~/BeagleBoard/oe/build/tmp-angstrom_v2012_05-eglibc/work'''
host$ '''find . -name "*busybox*"'''
The ''find'' command will find all files and directories that contain the name <code>busybox</code>.
BusyBox is not a Beagle specific compile, so it appears in a different location.  Change to the BusyBox directory and look around.  Can you find the source? Hint: they aren't in a git directory.
== Configuring BusyBox ==
== Configuring BusyBox ==

Revision as of 07:04, 22 October 2012

thumb‎ Embedded Linux Class by Mark A. Yoder

Compiling BusyBox

via git

Get the busybox sources from the busybox site

host$ git clone git://busybox.net/busybox.git
host$ cd busybox
host$ source ~/.oe/crossCompileEnv.sh
host$ make help
host$ make defconfig
host$ make -j9       # use -jX for X-1 cores

Configuring BusyBox

You can now configure BusyBox.

host$ make gconfig

After saving the configuration changes to update the .config file, it is a simple matter of running make.

host$ make -j9

My make took about 1.5 minutes to compile (25 seconds with make -j8!).

Copy it to your Beagle and test it out. Just typing busybox will tell you what commands it knows. Try some of them.

host$ scp busybox root@beagle:.
beagle$ busybox
beagle$ busybox ls

Try some other commands...

Shrinking BusyBox

How big is the busybox file? Try making it smaller by removing commands you don't use. How big is it if you just have ls? How much bigger is it when you add httpd? Try your own combinations. Report your findings to the class.

Static Linking

Some embedded systems are so small they don't have shared libraries. Recompile busybox to be statically linked. (Hint: look in configuration) How big it is? Does it still work?

Running a Web Server

Configure busybox to be a web server. Look under Networking Untilites, select httpd. How much more space does it take?

beagle$ busybox httpd

Yup, you are now running a web server. Your task is to figure out where to put the web pages it is serving. If you get something interesting going post your Beagle's address here. Hint: find httpd.c.

URL Name Notes Mark A. Yoder My first Beagle web page.

thumb‎ Embedded Linux Class by Mark A. Yoder